It’s more “it can’t hurt” than anything significant.
A generation ago, when brokers charged up to an 8% commission for purchases of mutual funds, they also charged a larger commission for “odd” lots (this depended on the stock, but was usually anything less than 100 shares) than a “round” lot (usually 100 shares).
Companies felt they got greater support from individual investors if their stock was at a price where most people could afford to buy a round lot. So companies whose strong earnings growth had driven the share price above that level would split, with 4-for-3, 3-for-2, 2-for-1 and 3-for-1 being among the most popular.
In today’s world, where wider bid-asked spreads have taken the place of commissions at discount brokers, a split may have some old-school appeal but is otherwise irrelevant, in my opinion.
In other markets, a split–or a stock dividend, which is basically the same thing in a different wrapper–may contain a signal of expected strong future earnings growth. But I don’t think this has ever been the case in the US market.
Finance academics back in the day did research establishing that stocks that split had sub-par performance in the months after the split became effective. This shows, they argued, that splits mean nothing. This completely missed the point. The academics overlooked (what a surprise) that stocks that split–like WMT did often in its glory days–outperformed during the months between the split being announced and its becoming effective. Some, WMT in particular, also tended to outperform in anticipation of a coming split announcement.